As wireless networks evolve and grow in complexity, there are ongoing challenges associated with reaching targeted coverage levels. Recently, in an effort to boost coverage and enhance throughput in wireless networks, network operators have proposed deployment of wireless devices capable of transmitting at a maximum allowable transmission power that is higher than a current maximum allowable transmission power of off-the-shelf wireless devices and/or other currently deployed standard or low powered wireless devices.
As shown in Table 1 below, the maximum allowable transmission power for wireless devices can be defined by the power class of the wireless device.
TABLE 1Power Power Power Power Class 1Class 2Class 3Class 4Wireless Wireless Wireless Wireless Opera-DeviceDeviceDeviceDevicetingPowerTol.PowerTol.PowerTol.PowerTol.Band(dBm)(dB)(dBm)(dB)(dBm)(dB)(dBm)(dB)Band I31±226±223±221±2Band II——26±223±221±2Band III————23±221±2
For example, the maximum allowable transmission power level and tolerance (i.e., power error limits) with which wireless devices can transmit data on a given frequency band or sub-band (e.g., bands I-III) can be specified based on a pre-defined power class (e.g., power classes 1-4 illustrated in Table 1) of the wireless device rather than a physical maximum transmit capability of the wireless device. Off-the-shelf and/or other standard-powered (or low-powered) wireless devices are currently defined in LTE as power class 3 and/or power class 4 wireless devices. Power class 3 and/or power class 4 low-powered wireless devices can be configured with a maximum allowable transmission power level of +23 dBm for frequency bands I-III with a nominal power tolerance of ±2 dB (e.g., for E-UTRA bands). High-powered wireless devices are currently defined as power class 1 or power class 2 wireless devices. Power class 1 and/or power class 2 high-powered wireless devices can be configured with a maximum allowable transmission power level of +26 dBm for frequency bands I-II with a nominal power tolerance±2 dB (e.g., for E-UTRA bands), as illustrated in Table 1.
Introducing additional high-powered wireless devices into a wireless network can negatively affect uplink system performance. For example, transmissions from standard-powered wireless devices (uplink transmissions) as well as signals received at the standard-powered wireless devices (downlink transmissions) may each be subject to interference caused by uplink transmissions from high-powered wireless devices operating in a high-powered transmission mode, particularly when both standard and high-powered wireless devices are operating on the same frequency band or sub-band.
Overview
Exemplary embodiments described herein include systems, methods, and processing nodes for minimizing interference that may potentially be caused by high-powered relay wireless devices operating in a high-powered transmission mode. Exemplary methods for minimizing interference include determining that a relay wireless device is operating in a high-powered transmission mode, wherein the relay wireless device is configured to relay data between a serving access node and an end-user wireless device, determining that an interference level of uplink signals received at a neighboring access node in communication with the serving access node meets a threshold, and deactivating the high-powered transmission mode of the relay wireless device. The high-powered transmission mode utilizes a first transmission power level that is associated with a high power class.
Exemplary systems for minimizing interference include a processing node that is configured to perform operations including determining that a relay wireless device assigned a high power class is attached to a first access node, wherein the high power class enables a high uplink transmission power level, transmitting an instruction to a second access node to monitor a signal level of uplink transmissions received at the second access node, wherein the second access node is communicably coupled to the first access node, receiving an indicator of a low signal level from the second access node, and transmitting an instruction to the relay wireless device to utilize a low uplink transmission level.
Exemplary processing nodes for minimizing interference configured to perform operations including identifying a high-powered relay device attached to a first access node, instructing a second access node to report interference caused by the high-powered relay device to uplink transmissions received at the second access node, receiving an indicator of interference from the second access node, and instructing the first access node to deactivate a high-powered transmission mode of the high-powered relay device.